Experimental Evaluation of Fluidic Flexible Matrix Composite Actuators
Open Access
- Author:
- Wimmer, Benjamin Michael
- Graduate Program:
- Aerospace Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- May 24, 2012
- Committee Members:
- Charles E Bakis, Thesis Advisor/Co-Advisor
Dennis K Mc Laughlin, Thesis Advisor/Co-Advisor - Keywords:
- FMC
Flexible Matrix Composites
Actuators
Composites
Active Structures - Abstract:
- A unique quality of composites made with a stiff reinforcement fiber and soft matrix material is that they are able to deform in complicated ways when stresses are applied due to highly directional stiffness properties. When this ability is employed in a tubular structure filled with fluid, interesting shape and stiffness changes can occur as a function of the pressure applied to the fluid. These tubes, called fluidic flexible matrix composites (F2MCs), are a new type of adaptive material. Until recently, most research and experimentation on F2MCs has been with simple thin walled filament wound tubes. There is currently a push to develop different variations of this concept suitable for a variety of applications. For example, some applications call for embedding the F2MC tubes into stiffer materials and others might need smaller and lighter tubes than those that can be made by filament winding. The objectives of this investigation are to investigate the performance filament wound F2MCs embedded into stiffer media and the performance of small-diameter braided F2MCs. Three main ways were employed to evaluate the performance of F2MC’s: free axial strain versus pressure; axial force versus pressure in the blocked condition (no axial strain); and the axial modulus of elasticity without any internal fluid. Some key results obtained from these test include large underperformances of F2MC actuators versus predictions, especially in several of the blocked force tests. As can be expected, large drops in performance accrued when F2MCs were placed into a stiff medium. It was also found that small diameter braided F2MCs could be made and used as actuators. It is suggested that more research into the three dimensional properties and states of deformation of the various composites might improve correspondence between theory and experiments. Factors such as interlaminar shear deformation, viscoelasticity, and end effects due to the grip fittings should be further explored, as well.